220 Proceedings of the Royal Physical Society. 



Were 2^^cioral incmhers present ? — I have now examined 

 with the utmost care a very great number of specimens of 

 Coccosteus decipiens in all conditions of preservation and from 

 all the beds and localities of the Scottish Old Eed Sandstone 

 which have yielded such remains, including the collections in 

 the British Museum, in the Museum of Practical Geology, in 

 the Edinburgh Museum of Science and Art, the Gordon- 

 Camming collection at Forres, and many others, but without 

 meeting with any other parts either of endo- or exoskeleton 

 than those I have described. And, in particular, I have not 

 seen the smallest evidence of the presence of any pectoral 

 limb, nor any trace of an articular surface on any of the 

 bones to which such a limb could have been articulated. It 

 can scarcely be believed that had such a limb been present it 

 would either have escaped preservation or observation in so 

 large a number of specimens. Nevertheless, more than one 

 author has been disposed to believe in the presence of such a 

 limb in Coccosteus. 



In the restored figure of Coccosteus given by Hugh Miller 

 in the first edition of the " Old Red Sandstone " (2, pi. iii.), 

 no limb is represented, and its absence is positively affirmed 

 in the text. But in subsequent editions, and also in Duff's 

 "Geology of Moray" (3, pi. viii., fig. 1), a peculiar 

 " paddle - shaped " body is represented appended to the 

 head. However, Hugh Miller, in a footnote, explains that 

 he has ascertained that the supposed arms " were simply 

 plates of a peculiar form." Of course there is not the 

 smallest doubt that the idea of this limb owed its oriiiin to a 

 displaced maxillary bone. 



But more recently, in connection with what appear un- 

 doubtedly to be fragments of a large and peculiar form of 

 Coccosteus, Trautschold (9 and 11) has described and figured 

 from the Old Red Sandstone of Russia certain peculiar 

 bodies, which he considers, though not without doubt, to 

 appertain to supposed large arms or " Ruderorgane " belong- 

 ing to that species, which he accordingly names Coccosteus 

 meyalo'ptcryx. What the fragments are to which he applies 

 the term " Oberarm " I have not the slightest idea, as I have 

 not seen them, and certainly nothing like them has ever 



